The present invention relates to protein-based, nutritious and multifunctional artificial dog bones and chewable pet toys. The present invention also relates to methods of preparing such chewable pet toys and dog bones.
For many people, dogs and other pet animals play an important role in providing happiness and safety in the family environment. People are becoming more concerned about the health and hygiene of their dog or pet. Chewable toys and artificial dog bones are commonly used to help massage the gums and to strengthen and clean the teeth of the dog or pet. As the animal expends chewing energy on the artificial bone or chewable pet toy, the animal is also less inclined to destructively chew on household objects.
There are several artificial dog bones or chewable pet toys currently marketed. The FLEXIBONE Nylon Chew, disclosed in U.S. Pat. No. 5,339,771, is made of molded synthetic thermoplastic having animal meal dispersed in the plastic polymer. This dog chew is strong and causes no tooth wear which can occur with natural bones, but it is not edible. Because the synthetic polymer is not biodegradable, it can potentially harm the environment.
Another commercially available artificial dog bone or pet chew is made of corn starch-based material with inert materials, such as xe2x80x9cOL""ROY Dog Chewsxe2x80x9d marketed by Wal-Mart Stores, Inc. Yet another pet chew product, sold as BOODA VELVETS dog chews, is made of a natural corn starch vinyl-alcohol copolymer, as disclosed in U.S. Pat. No. 5,419,283. The OL""ROY and BOODA VELVETS dog chews are not useful edible products in that they lack nutritional value. They do not replace or supplement the dog""s regular required diet or nutrition.
Many artificial dog bones are made of beef hides or pigskin. Examples of such artificial dog bones include HARPER""S CHEWBLER BONE made from beef hides and NATURAL BONES RAWHIDE CHEW TREATS produced by Pet Expo. These products possess a natural flavor, but they lack nutritional content. Moreover, artificial chewing toys made of rawhide are usually quickly destroyed by the chewing action which breaks down the structure of the material.
In all cases, care must be exercised when the dog is an aggressive chewer and is capable of breaking off an unusually large piece of the artificial dog bone or dog chew.
It will be appreciated that there is a need in the art for artificial dog bones and chewable pet toys which are durable, strong, improve oral hygiene, and provide nutritional value to the dog or pet.
Such artificial dog bones and chewable pet toys are disclosed and claimed herein.
The present invention is directed to edible chewable pet toys, such as artificial dog bones, and to methods of preparing such chewable pet toys. The chewable pet toys within the scope of the present invention are preferably made from protein-based thermoplastic composition containing plant and animal derived proteinic material and various additive and nutrient ingredients. Chewable pet toys within the scope of the present possess properties of conventional artificial dog bones made of synthetic polymer, such as good strength and hardness. In addition, the chewable pet toys contain nutrients and other ingredients to help keep teeth and bones strong and to promote the growth and health of the pet.
The edible and chewable pet toys within the scope of the present invention are preferably prepared from protein-based thermoplastics. The protein-based thermoplastic composition is made from plant protein, such as soy protein isolate, soy protein concentrate, gluten (such as wheat, oat, or rice gluten), corn zein, hordein, avenin, kafirin, or a combination thereof, alone or combined with animal protein, such as collagen, casein, albumin, gelatin, keratin, natural beef hides, pigskins, or chicken skins.
The protein can be a native protein or a chemically modified protein. Native protein is unmodified protein. Chemically modified protein includes hydrolyzed protein which provides better processing flowability. In order to improve water resistance of the protein, an organic acid can be used to adjust the pH of the protein composition to a pH between 4.5 and 6.5. Typical organic acids include lactic acid, malic acid, citric acid, tartaric acid, acetic acid, succinic acid, etc. Chemically modified proteins also include proteins treated with anhydrides.
The protein-based thermoplastic composition also preferably contains various nutrient ingredients to keep bones strong and to promote the growth and health of dogs and pets. Such nutrient ingredients can include vitamins, minerals, crude and dietary fibers, dried meat floss, and flavorings. Typical flavorings include beef, pork, and chicken flavors commonly preferred by dogs and pets. The other additives, such as anti-tartar agents and fresheners can be used to help clean teeth and promote good oral hygiene.
Processing aids, such as plasticizers, can be used to improve flowability of protein-based molding composition. Preservatives can also be used to maintain the freshness and edible character of articles prepared from the protein-based thermoplastic composition.
The present protein-based molding composition has good processing flowability, excellent mechanical properties such as a tensile strength from about 20 to 40 MPa and a Young""s Modulus from about 800 to 4000 MPa, and good water resistance with water absorption between about 80 to 250 wt. %.
In the present invention the protein-based thermoplastic composition can be easily shaped by injection molding, compression molding, transfer molding, pressure forming, or other similar molding methods. The present invention is preferably molded or shaped into the form of a chewable pet toy or into a configuration mimicking a natural animal bone, such as the molded bone shape shown in FIG. 1.